1. Field of the Invention
This invention relates to liquid dispensing pumps of the type in which a finger-actuated plunger powers a reciprocal piston pump. More particularly, this invention is directed to an arrangement including such a pump in which a push-button, finger-depressible dispensing head is rotatable to various predetermined rotational positions, and in which means are provided for varying the stroke distance of the dispensing head according to the selected rotational position thereof.
2. Brief Description of the Prior Art
Many finger-powered dispensing pumps have been previously proposed, including pressure-accumulating dispensing pumps such as that disclosed in my U.S. Pat. No. 3,414,169.
These pumps can be arranged as sprayers or atomizers in which a spray nozzle emits the pumped liquid as a spray, as shown in U.S. Pat. No. 3,194,447. Alternatively, the pumps can be arranged as liquid dispensers in which a dispensing nozzle thereof is a discharge spout, as shown in my U.S. Pat. No. 3,216,625.
It has been desired that means be provided for metering the amount of liquid dispensed, and also that such means be easy for a consumer to operate. For example, if the pump is used on a spray dispensing bottle for a hair spray, a consumer may desire full measure of hair spray with each actuation only when he or she is styling his or her hair. If only a touch-up is required, the consumer would desire that each actuation provide only a partial measure of the hair spray. Also, if the container with the pump thereon is to be stored or shipped, the consumer should be able to set the pump into a "lock" position wherein the dispensing arrangement is positively prevented from dispensing the contents of the container.
Previous attempts to provide limiting means have included plugs and/or cones disposed within the pump body to limit stroke length. However, the structure of these prior attempts has not been particularly sturdy, and the structural parts are easily broken by vigorous finger action on the sprayer head. Further, because the structure is disposed within the pump body, it is difficult to align the various measured-stroke positions thereof merely by changing the rotational position of the sprayer or other dispensing head. As a result, particular spray settings could not be accurately established. This drawback is further complicated in those devices in which the dispensing head can be removed from the hollow stem of the pump body and replaced in a different rotational orientation.
Consequently, it has been desired to construct a liquid dispensing pump arrangement whose structure avoids the drawbacks of the conventional devices, which has sturdy and reliable structure, and which permits positive setting into various full stroke, stroke-limited, and off positions, for example, by simple rotation of the dispensing head.